As a conventional vehicle control system for improving the fuel economy of a vehicle, for example, Patent Literature 1 discloses a controller of a power train having an engine, a friction-engaging device that is engaged/released to control the torque transmitted from the engine to a wheel, and a hydraulic pressure source that is driven by the power of the engine and generates the source pressure of the hydraulic pressure acting on the friction-engaging device. The controller of the power train can automatically change the engine from an operating state to a stopped state based on a predetermined condition.